During explosions on quarry ledges it is possible to hit elements of the quarry distribution network (CDN) with pieces of the blasted mass. This causes both direct damage, caused by damage to the elements of the CDN, and indirect damage - caused by the downtime of mining machines during the repair of damaged elements. In the periodical press there are still ongoing discussions about the distances safe for possible splintering of blast pieces. Drilling and blasting specialists have proposed several calculation formulas for determining the possible maximum spacing of blasted mass pieces. But the issue of power grid equipment in the danger zone is still unclear. In practice, the question of dismantling the PPC from the danger zone is solved intuitively, depending on the experience of operating personnel ...

In order to accept the most reliable variant of the quarry distribution network (CDN), it is necessary to calculate the reliability levels first of all.As the analysis of materials of emergency statistics on quarries (14 858 cases of CDN damages were considered) has shown, there is a linear dependence between damageability of separate elements of the scheme and the number of homogeneous elements. So, for example, damageability of flexible excavator cables is described by the equation ...

Implementation of complex mechanization and automation of mining operations can not be effective without the availability of reliable and economically feasible schemes of power supply of mine electrical receptors. To date, the reliability of circuits has been evaluated based on general considerations and the experience of the designer. Such a subjective decision has often led either to unnecessary redundancy and complication of the scheme, or to a decrease in the reliability of power supply. Generalization of operating experience for the past years with the application of probability theory and mathematical statistics has now allowed to develop scientifically justified methods of reliability assessment and construction of power supply systems of coal mines. The methods proposed by the author are based on the calculation of: 1) the probability of interruption of power supply to mine electrical receptors; 2) the mathematical expectation of losses; 3) the probabilities of accidents due to interruption of power supply to electrical receptors of the first category.